From af200eac54161e1e2134cfc590ab1d31193e77a4 Mon Sep 17 00:00:00 2001
From: "Brian J. Cardiff" <bcardiff@gmail.com>
Date: Thu, 2 Apr 2020 12:34:15 -0300
Subject: [PATCH 1/2] Comply exhaustive case check

Comply exhaustive case check
---
 spec/dummy_driver_spec.cr | 2 ++
 src/spec.cr               | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/spec/dummy_driver_spec.cr b/spec/dummy_driver_spec.cr
index 688a71d..41f4d10 100644
--- a/spec/dummy_driver_spec.cr
+++ b/spec/dummy_driver_spec.cr
@@ -246,6 +246,8 @@ describe DummyDriver do
               rs.read(Int64, Int64).should eq({3i64, 4i64})
             when 1
               rs.read(Int64, Int64).should eq({1i64, 2i64})
+            else
+              raise "unreachable"
             end
             i += 1
           end
diff --git a/src/spec.cr b/src/spec.cr
index b8c64c2..225a419 100644
--- a/src/spec.cr
+++ b/src/spec.cr
@@ -505,6 +505,8 @@ module DB
                 end
               end
             end
+          else
+            raise "Invalid prepared value. Allowed values are :both and :default"
           end
         end
       end

From f4b298d3a5a6c555e02fd681e5f0da6680e44e84 Mon Sep 17 00:00:00 2001
From: "Brian J. Cardiff" <bcardiff@gmail.com>
Date: Wed, 25 Mar 2020 10:56:03 -0300
Subject: [PATCH 2/2] Use select / timeout in Crystal 0.34

---
 src/db/pool.cr | 47 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/src/db/pool.cr b/src/db/pool.cr
index 5acffaa..75a8f93 100644
--- a/src/db/pool.cr
+++ b/src/db/pool.cr
@@ -206,25 +206,38 @@ module DB
       @idle.first?
     end
 
-    private def wait_for_available
-      timeout = TimeoutHelper.new(@checkout_timeout.to_f64)
-      sync_inc_waiting_resource
+    {% if compare_versions(Crystal::VERSION, "0.34.0-0") > 0 %}
+      private def wait_for_available
+        sync_inc_waiting_resource
 
-      timeout.start
-
-      # TODO update to select keyword for crystal 0.19
-      index, _ = Channel.select(@availability_channel.receive_select_action, timeout.receive_select_action)
-      case index
-      when 0
-        timeout.cancel
-        sync_dec_waiting_resource
-      when 1
-        sync_dec_waiting_resource
-        raise DB::PoolTimeout.new
-      else
-        raise DB::Error.new
+        select
+        when @availability_channel.receive
+          sync_dec_waiting_resource
+        when timeout(@checkout_timeout.seconds)
+          sync_dec_waiting_resource
+          raise DB::PoolTimeout.new
+        end
       end
-    end
+    {% else %}
+      private def wait_for_available
+        timeout = TimeoutHelper.new(@checkout_timeout.to_f64)
+        sync_inc_waiting_resource
+
+        timeout.start
+
+        index, _ = Channel.select(@availability_channel.receive_select_action, timeout.receive_select_action)
+        case index
+        when 0
+          timeout.cancel
+          sync_dec_waiting_resource
+        when 1
+          sync_dec_waiting_resource
+          raise DB::PoolTimeout.new
+        else
+          raise DB::Error.new
+        end
+      end
+    {% end %}
 
     private def sync_inc_waiting_resource
       sync { @waiting_resource += 1 }